At present, it is common for computer users to have a mousepad on which a computer mouse can roll, thereby moving a cursor on a monitor screen. Most often the mousepad rests upon a table or desk beside the computer itself Repeated use may cause the operator's arm and hand to grow tired or stiff. This may be because the arm must reach too far out, or at an awkward angle.
In other instances, a mouse may be used to move a cursor on, for example, a television screen on the far side of a room. A suitable table or desk may not be available, or may be inconvenient. In still other instances, a laptop computer can be small enough to be carried inside a briefcase. When traveling or using one's laptop computer in a small space, there may not be a convenient table top or other customary space for operating a conventional computer mouse.
In each of these instances it may be advantageous to have a mousepad that does not require a desk, table or like surface, but rather that can rest on a part of the user's body. For example, it would be advantageous to have a mousepad that can rest on the user's lap, thigh or upper leg.
At least two inventors have considered the problem of providing a mousepad that is portable and does not require a table or other large surface. U.S. Pat. No. 5,355,811 of Brewer, issued Oct. 18, 1994 discloses a small rectangular table that can be worn above a user's knee. The table is equipped with a pair of laterally adjustable blocks with curved sides for seating against the leg. U.S. Design Pat. No. 392,960 of Giorgio, issued Mar. 31, 1998, also shows a portable, flat mousepad surface. A mounting bracket with curved arms, such as might fit on a person's leg, emanates from the underside of the mousepad.
Illustrations in the two documents noted above show rectangular surfaces with the rectangle aligned perpendicular to the arms, or supports, that are available to engage the leg. A square or relatively sharp corner might wedge uncomfortably against the stomach. It would be advantageous to have a mousepad assembly that at least partially, accommodates the shape of the user's body. For example, when one is sitting it would be advantageous to have a mousepad that will lie on the lap, with one edge toward the torso. In such a position, the arm can be held relatively close to the body, perhaps with the elbow supported in a resting position on the armrest of a chair.
Typical computer mice have a track-ball with a rubberized coating captured within a socket. As the ball rolls against a surface the motion is converted into an electrical signal which causes the cursor to move on the screen of the computer monitor. Track-ball mice tend to be gravity dependent. Although it is customary to operate a mouse on a flat table, a gravity dependent mouse can usually operate on a moderate slant, and can usually operate on a surface that is not precisely flat, but has a modestly convex curvature. That is, a mousepad need not be perfectly flat or level, but can rest on an uneven surface, such as a person's lap or leg.
When a mousepad surface is placed above the knee, perhaps well up on the thigh, the hand holding the mouse does not generally work perpendicular to the leg and parallel to the leg. That is, the normal square orientation suggested by the illustrations of Brewer and Giorgio does not reflect actual operation in a user's hand. More typically, a mouse is held in the working hand, with the base of the palm of the hand resting against the mousepad in the near corner. Motion of the cursor in the `X` direction (that is, across the width of the monitor screen) tends to occur when the user rocks the hand at the wrist, moving the mouse generally diagonally relative to the mousepad. In this rocking motion of the hand, the base of the palm usually remains in constant contact with the mousepad. Motion in the `Y` direction (that is, across the height of the monitor screen) tends to occur when the mouse user straightens or curls the fingers of the mouse holding hand. This `Y` motion involves a displacement from the near diagonal corner of the mousepad toward the far diagonal corner. Again, the heel, or base, of the palm generally remains in contact with the mousepad throughout the motion.
It would also be advantageous to have a mousepad that is rounded, and that has a relief, or recess to accommodate the curvature of the torso. It would be advantageous to have a mousepad that can be secured to the lap and thereby be encouraged to remain relatively steady while in use. It would also be advantageous to have a mousepad that is not necessarily intended to have a square or rectangular shape, and whose sides are aligned parallel or perpendicular to the axis of the upper leg bone. It would be advantageous to have a mousepad that can be secured to the upper thigh at an angle to the leg bone, and that has a region for the base of the palm to rest on in use.
When using a laptop computer, it would be inconvenient, and disadvantageous, to have a mousepad whose mounting bracket is so large that either it cannot fit easily within a briefcase. It would be preferable to have a mousepad assembly that would lie flat either within one of the divider pockets of the lid, or within a file folder.